Combustion apparatus with vaned fuel injector means



Nov. 25, 1952 M. NATHAN COMBUSTION APPARATUS WITH VANED FUEL INJECTOR MEANS 2 SHEETS-SHEET 1 Filed May 19, 1945 Wham 1952 M. NATHAN ,928

COMBUSTION APPARATUS WITH VANED FUEL INJECTOR MEANS Filed May 19, 1945 2 swam-smart 2 I nvcn for Patented Nov. 25, 1952 UNITED? STATES PATENT OFFICE COMBUSTION APPARATUS WITH VANED FUEL INJECTOR MEANS Matthew LewislNathan, Godalming, England, as} Signor to Power Jets (Research & Development) Limited, London, England Application May 19, 1945, Serial-No. 595,297 In Great Britain May 19, 1944 as carbon deposition or formationwhich are due to or related to the fact of the burner protruding into a region of reversed air flow or turbulence. Such a case exists, for example, in certain combustion arrangements. of gas turbine engines, where a flame tube in which the general direction of flow is axial, has a burner extending into one end of it axially, and where inorder (among other reasons) to hold the flame back into the burner'at very loW fuel flows, the air flow in the region of the burner is arranged" (usually by means ofswirlers) to have, a-core of reversed direction, 1. e. towards the burner. The invention seeks to obviate adverse effectswhich may arise in. such cases, and also tov perfect burner and combustion devices in which the burner itself has a plurality. of spraying jets arranged in rose fashionv or similarly, which arrangement may be peculiarly susceptible to carbon deposition or formation;

For this purpose, the invention providescombustion apparatus comprising-afuel burner associated with means for opposing'the production of gaseous vortex flow or large scale gaseous turbulence around said burner. Such means may comprise vanes or baffies which may be mounted on or form part of the burner body, in which case they may also have some effect as heat-exchanging fins, or they may be mounted as part of the surrounding combustion equipment, the former being preferred.

By way of example, two forms of embodiment of the invention will be hereinunder described with reference to the accompanying drawings in which:

Fig. l is a view in sectional elevation of one form of embodiment of the invention;

Fig.2 is a right hand end view of Fig. 1;

Fig. 3 is a section on the line AB of Fig. 1;

Fig. 4 is a view in sectional elevation of a second form of embodiment of the invention.

Fig. 5 is a view in longitudinal section of the embodiment of the invention shown in Fig. 1 as it appears in a typical installation in a flame tube.

Referring to the drawings and more particularly to Figs. 1 and 2, the burner body comprises a hollow cylindrical portion I having an axial bore 2 which can be supplied with fuel under pressure through a union 3 which is screw threaded to the cylinder I at its external or rear end. The union Gil -39172.)

. 2 H. 3 is provided with a fiat surface i6 against; which can bear a grub screw- I2 for the purposes of securing the union 3 rigidly-to the body. I. At its inner or forward end the burner body comprises afrusto-conical portion [0- which together with a central portion I3; provide seven channels II of w ich i are arranged symmetrically ar und the axis of the burner body andthe. seventh is; centrally located. 7

Each channel I I; is provided witha nozzle element 4 so that six; of such nozzlesdare arranged symmetrically aroundthe axisof; the cylinder I and protruding in divergent directions, while, a seventh centralnozzle; element 4-is also, provided which is directed axially:

The; nozzle elements 4 are screw threaded into the walls of thechannels, I I and: a plugrS is screw threaded into each nozzle element. Each nozzle 4 is provided with swirling means for producing a rapid swirling motion in the, fuel before it is ejected through the. orifice I! of each nozzle 4. The construction of; one, form of such swirl means is shown in Fig. 3 wherein the swirlingv device 3 comprises a circular chamber I4 towhich fuel is admitted from the space I8 by means of two, tangentially directed channels I5 which are staggered. so as not to be diametrically opposed so, that fuel entering chamber I4 through these channels I5 is given a rapid, swirling motion as indicated by the arrows. Each nozzle element l is provided with a flattened portion to form a communicating duct for the fuel between the channel II and the channels I5.

On the outside of the cylindrical portion I and lying substantially in axial-radial planes are provided a, plurality of vanes I which are integral with or intimately attached to the body I and are preferably located as close as possible to the burner face. These vanes I are shaped at their margins to correspond with the internal shape of the combustion chamber in which the burner is operating so that they form, in effect, baiiles intercepting the space between the burner body I and the end wall (and in some cases the side wall also) of the chamber (as shown in Fig. i) It has been found satisfactory to provide the same number of vanes I as there are lateral nozzles 4, e. g. six in the example illustrated.

In Fig. 4 a second form of embodiment of the invention is shown in which the vanes I are attached to the inner surface of the end wall 22 of a, combustion chamber in which the burner is operating. In this case also, the vanes -I are symmetrically arranged as in Fig. 2, a central and axial gap being left between the vanes 7 for the 3 insertion of the burner. The vanes 1 may be secured to the wall 22 by any suitable means, for example by welding along the edge [9. A ring 20 is integral with the Wall of the combustion chamber and serves to hold the burner firmly in position. A ring 2| is attached to the burner body I after the burner has been inserted to prevent excessive movement of the latter.

The function of the vanes l is to prevent vortex flow around the burner body I which flow may produce a core reversal near the burner with consequent carbon deposition on the burner face.

In Fig. 5 there is shown a burner according to Fig. 4 in a typical installation, in this case a, flame tube of the type described in Lubbock et al. Patent No. 2,398,654. The flame tube 25 is provided with swirlers 23 and 24 which produce a vortex flow having a core of reversed direction towards the burner, i. e., from right to left as shown in the drawing. The burner I extends axially into the flame tube 25 and, as shown in Fig. 4, is provided with a coaxial annular wall 22 Which partially blocks the flow of air through swirlers 23 in the end of the flame tube 25. Vanes l are attached to this wall, and as explained above, they prevent vortex flow occurring in the immediate vicinity of the burner I.

As a secondary function, the vanes I hel in pre-heating the fuel, the pre-heat at low fuel flows being considerable. This has the added advantage of decreasing the flow for a given pressure, thus increasing the range of the burner.

The burner described and constituting a feature of the invention, namely one with a plurality of divergent nozzles each with its own swirl chamber, is very simple and can be made to afiord good atomisation over a wide range.

I claim:

1. Combustion apparatus comprising a flame tube through which a combustion-supporting gas flows in a generally axial direction, a fuel injector extending axially into one end of said tube, an injection nozzle at one end of said injector, entry means into said tube for the gas, swirler means to produce a vortex flow in said tube having a core of reversed direction axially toward said nozzle, wall means in supporting relationship with said injector and extending coaxially therewith to define a chamber, a plurality of axially extending vanes disposed in circum- 4 ferentially spaced relation around said injector and extending radially for the major portion of the distance between said injector and said wall means to divide said chamber into pockets, and said wall means closing said pockets at their ends remote from said nozzle.

2. Combustion apparatus comprising a flame tube through which a combustion-supporting gas flows in a generally axial direction, a fuel injector extending axially into one end of said tube, a plurality of injection nozzles symmetrically disposed and each protruding in a difierent direction at one end of said injector, entry means into said tube for the gas, swirler means to produce a vortex flow in said tube having a core of reversed direction axially toward said nozzles, wall means in supporting relationship with said injector and extending coaxially therewith to define a chamber, a plurality of axially extending vanes disposed in circumferentially spaced relation around said injector and extending radially for the major portion of the distance between said injector and said wall means to divide said chamber into pockets, said wall means closing said pockets at their ends remote from said nozzles, and said vanes and nozzles being circumferentially alternated.

MATTHEW L. NATHAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

